Water tube boiler.



A. D. PRATT.

WATER TUBE BOILER.

AYPLIOATION 211.31) 111111111 2.

H F j I 1/ INVENTOR Mam was era-res ERNIE OE NEW-YORK, IQ. Y., ASSIGNORTO THE EBABCOCK & WILCOX COI- BANY, GE BAYENNE, NEW-JERSEY, LCOBBQBATQONOF. NEW JERSEY.

warez-ma norms.

I Specification of Letters ream.

Patented Feb. 4, 1913.

To all whom it may concern:

Be it known that I,- An'rHUR-D. Piwrr, a

citizen of the United States, residing in New- York city, borough ofManhattan,- in the county of New York and State of New York, i

ing a bank of inclined water tubes, are-symmetrically arranged above acommon fuel chamber extending from one side of the boiler to the otherand fired at both thefront and rear. The disposition of the boiler unitsprovides an A-shaped combustion chamber of large volume, separateportions of the furnace gases being directed from the central combustionchamber in independent streams toward the outlet fines.

The invention will be understood by reference to the accompanyingdrawing which is a section through a boiler embodying the invention.

In the drawing I have shown two units each comprising a bank of inclinedwatertubes, the tubes 1 of the left hand unit being expanded into lowerandupper headers 2 and 3, and the tubes 4 of the right hand unit beingexpanded into lower and upper headers 5 and 6. These headers extendtransversely of-the boiler from one side wall of the setting to theother side wall. Each bank is divided by transverse bafiles 7 and 8, thebattles 7 rising from bafiles 9 supported upon the lowermost row oftubes and extending from the lower headers toward the rear, thusproviding a plurality of transverse passes for the gases across andaround the tubes, as indicated by the arrows. The upper headers 3 areconnected by short vertical pipes 10 with a longitudinal steam and waterdrum 11, and the latter is connected with the lower headers by pipes 12.The upper headers 6 are connected by short vertical pipes 13 with alongitudinal steam and water drum 14, and the latter is connected withthe lower headers 5 by pipes 15. Walls 8' extend from the transversebattles 8 to the drums 11 and 14:, and inthe space between these wallsand the roof of the setting above the banks of tubes, and above thefirst and second passes, are placed superheaters 16 and 17 of anyapproved type. In the form shown these conisist of transverse boxesconnected by U- .sba-ped pipes, the upper boxes being conpected to thesteam spaces of the correspond- ;ing drum.

The boiler units above described are suspended over a common furnaceextending from the front to the rear of the boiler. In thedesign shown,the furnace is divided galong lts center by a low wall 18 extending?transversely of the setting from one side wall to the other. This wallserves as a rear wall {for the two fuel bed sections, in this instancetwo chaln grate stokers, 19 and 20 of any apiproved construction, andoperated independently of each other, one from the front and the otherfrom the rear of the setting. The

fmud' drums 25 of the boiler are at the rear of and protected by theignition arches 21 and 22.

The-two boiler units are so disposed relat1ve to each other that theupper headers 3 and 6 converge toward each other downwardly and theirlower ends are in proximity to the central transverse vertical plane ofthe setting. There is thus provided a large A-shaped combustion chamber23 common to the boiler units. To insure against burning the lower endsof the upper headers I nipple to said headers transverse boxes 24:, thelowermost row of tubes of the bank being expanded into said boxes andinto the mud Y drums 25.

Inthe present design I connect the upper I headers. 3 and 6, through theboxes 24, by a series of shortcirculation pipes 26 covered by roof tiles26. The A-shaped combustion chamber is therefore closed at the apex andis open only along the upper portions of the inclined sides thereof,that is, at the uptake ends'of the inclined tubes. The gases from thecombustion chamber divided into separate streams, enter the banks oftubes at their uptake ends and, following the path indicated by thearrows, escape through the enced through a stream or lane of excess airor unconsumed combustible gases passing through the boiler and escapingto the stacks will be avoided.

The angle of inclination of the tubes and the heating surfaces isapproximately 45 to the horizontal, and the planes of the upper headersapproximately at an angle of 90 to each other. I do not however restrictmyself to these angles, the essential feature being the disposition ofthe units relative to each other over a common furnace and combustionchamber to provide an I l-shaped combustion chamber of relatively largevolume.

In my application Serial No. 707,420, filed July 3, 1912, I havedescribed a water tube boiler of the same general type as describedherein, the design shown in said application comprising a transversedrum at the apex of the combustion chamber to which the lower ends ofthe upper headers are nippled.

What I claim is:

1. In a water tube boiler, the combination of two units each comprisinga bank of inclined water tubes, lower and upper headers into which saidtubes are expanded, said units being so disposed that the upper headersconverge toward each other downwardly, pipes connecting said upperheaders with each other, drums located above and connected with thelower and upper headers of the corresponding unit, and a centralcombustion chamber common to said units.

2. In a water tube boiler, the combination of two units each comprisinga bank of inclined water tubes, lower and upper headers into which saidtubes are expanded, said units being so disposed that the upper headersconverge toward each other downwardly, pipes connecting said upperheaders with each other, and a bathe in each unit extending from thelower header toward the upper, whereby an A-shaped combustion chamber isprovided common to the two units and open to the gases along the upperportions of the inclined sidesthereof, and a furnace chamnoaneia berextending from the front to the rear of theboiler.

3. In a water tube boiler, the combination of two units each comprisinga bank of inclined water tubes, lower and upper headers into which saidtubes are expanded, said units being so disposed that the upper "headersconverge toward each other downwardly, pipes connecting said upperheaders with each other, superheaters above said banks of tubes, and acentral combustion chamber common to said units.

4:. In a water tube boiler, the combination of two units each-comprisinga bank of in clined water tubes, lower and upper headers into which saidtubes are expanded, said units being so disposed that the upper headersconverge toward each other downwardly, pipes connecting the lower endsof the upper headers, transverse baflies dividing said banks into aplurality of passes beginning at the steam uptake ends, and a baffleextending from therearward to the first pass, whereby an Ah-shapedcombustion chamber is provided common to the two units and open to thegases along the upper portions of the inclined sides thereof, and afurnace cham-.

ber extending from the front to the rear of the boiler.

5. In a water tube boiler, the combination of two units each comprisinga bank of inclined Water tubes, lower and upper headers into which saidtubes are expanded, said units being so disposed that the upper head-ARTHUR l).- PRATT.

Witnesses:

CHAnLns A. Joints, M. E. ll/lohlmon.

